#pragma once

#include <string>

namespace kratos { namespace corelib {

static std::string base64_chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

struct Base64 {
    static inline bool is_base64(unsigned char c) {
        return (isalnum(c) || (c == '+') || (c == '/'));
    }

    static std::string base64_encode(unsigned char const* bytes_to_encode, unsigned int in_len) {
        std::string ret;
        int i = 0;
        int j = 0;
        unsigned char char_array_3[3];
        unsigned char char_array_4[4];
        while (in_len--) {
            char_array_3[i++] = *(bytes_to_encode++);
            if (i == 3) {
                char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
                char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
                char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
                char_array_4[3] = char_array_3[2] & 0x3f;
                for (i = 0; (i < 4); i++) {
                    ret += base64_chars[char_array_4[i]];
                }
                i = 0;
            }
        }
        if (i) {
            for (j = i; j < 3; j++) {
                char_array_3[j] = '\0';
            }
            char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
            char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
            char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
            char_array_4[3] = char_array_3[2] & 0x3f;
            for (j = 0; (j < i + 1); j++) {
                ret += base64_chars[char_array_4[j]];
            }
            while ((i++ < 3)) {
                ret += '=';
            }
        }
        return ret;
    }

    static std::string base64_decode(std::string const& encoded_string) {
        int in_len = encoded_string.size();
        int i = 0;
        int j = 0;
        int in_ = 0;
        unsigned char char_array_4[4], char_array_3[3];
        std::string ret;
        while (in_len-- && (encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
            char_array_4[i++] = encoded_string[in_]; in_++;
            if (i == 4) {
                for (i = 0; i < 4; i++) {
                    char_array_4[i] = (unsigned char)base64_chars.find(char_array_4[i]);
                }
                char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
                char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
                char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
                for (i = 0; (i < 3); i++) {
                    ret += char_array_3[i];
                }
                i = 0;
            }
        }
        if (i) {
            for (j = i; j < 4; j++) {
                char_array_4[j] = 0;
            }
            for (j = 0; j < 4; j++) {
                char_array_4[j] = (unsigned char)base64_chars.find(char_array_4[j]);
            }
            char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
            char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
            char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
            for (j = 0; (j < i - 1); j++) {
                ret += char_array_3[j];
            }
        }
        return ret;
    }
};

}}
